Container



' Sept. 22, 1970 R. L. IGNELL 3,529,647

CONTAINER Filed Sept. 10, 1968 United States Patent 3,529,647 CONTAINER Rolf Lennart Ignell, Lund, Sweden, assignor to Sobrefina S.A., Fribourg, Switzerland, 21 Swiss corporation Filed Sept. 10, 1968, Ser. No. 758,832 Claims priority, application Sweden, Sept. 25, 1967, 13,128/ 67 Int. Cl. B65d 23/08 U.S. Cl. 150-.5 3 Claims ABSTRACT OF THE DISCLOSURE A container for liquids containing pressurized gas is provided in which the container is made of a flexible, elastic plastic material surrounded by a substantially inflexible sleeve extending beyond the bottom of said container whereby expansion due to the pressurized gas will take place longitudinally While remaining protected by the sleeve.

This invention is concerned with a container for pressurized liquids, at least part of the contents consisting of gas.

Packages of glass or sheet metal have so far been used for the packaging of pressurized liquids which at least in part consist of gas, e.g., beer, Vichy Water, etc. The reason why just these packaging materials have been used is that they satisfy the requirements that are set as regards impermeability, at the same time as they are mechanically stable.

A number of plastic materials have lately come on the market, which after suitable treatment can be used for pressurized liquids and which then have characteristics that the materials known earlier have not. Such a material is, e.g., polyvinylchloride which has been coated or varnished with polyvinylidene chloride known commercially as Saran in order to attain the required impermeability to gases. As a result of the inside pressure that is present in, e.g., beer packages, the plastic container will undergo a change in shape due to the wall material being strained. This is naturally a certain disadvantage, since the aim within rational transportation technology is to have fixed dimensions for bottles and packages. It has been found further that there is a danger of spillage by splashing when a container is opened and the container walls suddenly resume their original positions. On the other hand, the said straining of the wall material means an increase in the volume of the container which in certain cases is an advantage.

When conventional beer bottles of glass are filled, the bottles are not completely filled. The reason why the bottles are not completely full when closure is effected is that the danger of explosion, when a completely full bottle of nonelastic material, e.g. glass, is heated, is to be avoided, and that there should be a small cushion of gas next to the opening of the bottle in order to enable the bottle to be opened without spillage.

When using flexible containers in accordance with the invention, the bottles can be completely filled and then capped without any of the contents being removed. The reason for this is that the walls of the container are flexible and the introduction of the pressurized liquid thus means that the volume of the container increases. The increased volume is naturally immediately filled by the gas liberated by the liquid, e.g., in this case beer, and when the container is brought into the opening position, i.e., is held so that the opening of the container is towards the top, the cushion of gas will naturally come to be situated next to the opening of the container. In conventional glass bottles which are not filled completely there Patented Sept. 22, 1970 ice is formed a cushion of gas which, when the liquid is beer, contains partly carbon dioxide and partly oxygen.

The carbon dioxide is naturally made up of gas liberated from the liquid while the oxygen is from the air that has been trapped in the bottle when it was capped. The oxygen oxidizes certain taste constituents in the beer which means that its quality deteriorates. It is therefore desirable that it should be possible to exclude oxygen, but this is diflicult, since the bottles are not completely filled and the capping machines are generally of open construction which do not prevent air getting into the bottles.

The disadvantages inherent in known plastic containers are pressurized liquids, e.g., the danger of splashing when the containers are opened, and the phenomenon that the walls, which had been stretched by the pressure inside, soon resume their original positions, are removed by the invention, which is characterised by the container being at least partly produced from a flexible plastic material which, when pressure is released, only resumes its original position slowly; by a flexible plastic lining capable of closure and by a stiff sleeve of, e.g., cardboard or sheet metal surrounding the said plastic lining, by which means the straining and deformation of the plastic lining, brought about by the pressurised liquid contents, results in the main in an increase in the length of the lining surrounded by the sleeve, and by the wall material of the container consisting of polyvinylchloride comprising an elastomer, e.g. ABS.

The invention will be described below with the aid of the attached diagrammatic drawing, which shows a container partly in cross section in accordance with the invention. The figure thus shows a closed plastic container 2 of, e.g., polyvinylchloride coated with Saran that has had an elastomer, such as acrylonitrile-butadiene-styrene resin hereinafter referred to as ABS, added to it, which container has a cylindrical central portion and two curved end portions, one of which is provided with a capping device 5. The container 2 is surrounded by an outer sleeve 1 which is made from a material that is stiff and only slightly flexible, e.g. cardboard or a similar material. The container 2 is arranged in relation to the outer sleeve 1 in such a way that the sleeve projects beyond the bottom end of the container and serves as its support. There is in the container 2 a liquid 4 and gas 6.

It is most convenient if the container is inserted into its outer sleeve 1 prior to the introduction of the pressurised liquid, this filling operation being preferably carried out with the liquid at a low temperature. When container 2 has been completely filled by the liquid, the impermeable cap 5 is put on, after which the filling operation is complete.

After some time, and especially if the container with its contents has been stored at room temperature, the pressure in container 2 increases, which results in the walls of the plastic container being strained. Since sleeve 1 prevents expansion in the transverse direction, the container will instead expand longitudinally in the direction of sleeve 1, assuming finally the position 3 indicated by the dotted line. This expansion of container 2 is accompanied by an increase in volume which means that the liquid inside the container will not fill the whole space, and that the excess space will instead be taken up by the gas liberated by the liquid which was previously dissolved in the liquid. The most usual gas which is likely to be encountered is carbon dioxide which is dissolved in, e.g., beer and Vichy water.

When the pressure inside the container and the tension in the walls have reached an equilibrium condition. the container will not expand any more, and the container is ready for use in the same way as conventional glass bottles, i.e., the cushion of gas 6 formed below cap 5 prevents spillage when the container is opened by removing cap 5. The container body 2 gradually returns to its original shape, i.e., the stretched walls shrink. This process however, takes place very slowly if the material used, consists of a polyvinylchloride or a plastic material having similar properties and an elastomer, e.g. ABS, and will not cause the contents to splash out as a result of the contraction of the container.

The container in accordance with the invention has been found very advantageous, since it is low in weight in comparison with conventional glass bottles, is cheap and can be easily destroyed by burning. It will also not break when dropped to the ground and will not produce sharp splinters which easily injure men and animals. The diameter of the container is stable as a result of the outer sleeve 1, and the greater part of the deformation of the container is on the whole concentrated to the cylindrical central portion of the container body situated in the sleeve 1, which portion undergoes an extension. Since the deformed portion of the container is completely enclosed in the outer sleeve 1, there will be no inconvenience when the container is transported and handled.

It is naturally possible to modify the appearance of the container within the framework of the idea underlying the invention, and the upper portion of the container procontainer from the sleeve 1 can thus be shaped as, e.g., a truncated cone or be given any shape whatever. It is however, an advantage if the end portions are dome-shaped, since in this case the tensile stresses will be uniformly distributed over the whole surface of the end portions, which means that the least possible deformation or change of dimensions will occur in these portions of container 2.

What is claimed is:

1. A container for liquids containing a pressurized gas comprising an impermeable elastic container composed of polyvinyl chloride and elastomer, a sleeve of inflexible inelastic material surrounding and engaging said elastic container for restraining transverse expansion of said elastic container while permitting expansion of the elastic container by said pressurized gas longitudinally of said inelastic sleeve, said elastic container being capable, when the pressurized gas is released, of shrinking to its original size and shape gradually so that splashing of the liquid contained therein by rapid contraction of said elastic container will be prevented.

2. A container as claimed in claim 1 wherein said sleeve extends beyond the bottom of said container when it is in its longitudinally expanded state due to pressurized gas.

3. A container as claimed in claim 1 wherein the clastomer is an acrylonitrile-butadiene-styrene resin.

References Cited UNITED STATES PATENTS 2,709,024 5/1955 Lemoine 222-183 2,816,691 12/1957 Ward 222183 3,156,383 11/1964 Melli 222215 X 3,204,855 9/1965 Boynton 21511 X 3,325,030 6/1967 Rausing 21512 DONALD F. NORTON, Primary Examiner US. Cl. X.R. 

